Physical music requires an investment. For the most part it is a fairly expensive investment relatively speaking. To listen to online or streaming you only need your phone and earbuds.
What drove the vinyl resurgence was mostly an upper middle class / affluent segment that is aging and fairly limited. The other segment were the collectors who mostly deal in the used market. The authors questioning why the record companies don’t expand manufacturing and drive prices lower...why would they do that? This market doesn’t reward spending money on R&D or expanding manufacturing. The masses are NOT buying vinyl. This is a relatively small market and doesn’t justify spending the money. Best to take as much profit for as cheaply as possible.
I own vinyl, CD (SACD), and streaming (saved locally) of a number of albums. I don’t buy vinyl to collect, though many do. I buy for the listening quality. To that end, CD (SACD) offers me the best sound quality. This is especially true tor the Original Master Recordings on SACD format. Next would be one of the high quality streaming services I have over some high end headphones. These even rival the limited edition vinyl half-speed master recordings I have like Dire Straits "Brothers in Arms", which on my system the vinyl does sound very good.
Sadly, streaming is getting better and better. The people buying physical music just aren’t a large enough segment to keep it going to any great extent. Producing limited numbers of vinyl the old way actually serves the best purpose, scarcity with higher demand pricing.